This invention provides an apparatus for direct conversion of ocean wave motion into usable electric power. With the increasing attention given to the search for new sources of energy, the possibility of harnessing the energy of ocean waves becomes more and more tantalizing. Wave motion in the ocean is caused by winds, which in turn are the products of energy from the sun. Using the motion of the waves in the ocean is thus one way of benefiting from the virtually limitless amounts of energy available from the sun.
Attempts have been made to harness the motion of waves to produce electricity. The usual approach has been to devise an apparatus which causes the waves to drive mechanically a conventional turbine or electric generator. An analysis of the operation of such a device was described in an article by M. E. McCormick in "A Modified Linear Analysis of a Wave-Energy Conversion Buoy" which appeared in Ocean Engineering, volume 3, pp. 133-144. But serious practical problems remain with such conventional power generation systems. Both the generator and mechanical coupling required are subject to corrosive attack by the marine environment. The generator and coupling also, of necessity, have moving parts which require frequent maintenance.
The method and apparatus disclosed in the present invention does not involve a conventional generator, but rather comprises an electrochemical gas concentration cell which converts wave motion to electricity directly. The principle of direct conversion has been known on theoretical grounds, although no practical apparatus or method for extracting electrical energy from the ocean is known. The existence of protonic conduction in ice was demonstrated by P. N. Krishman, I. Young, and R. E. Salomon in volume 70, number 5 of the Journal of Physical Chemistry, pp. 1595-97. In this work, it was shown that protons, coming from hydrogen gas, were transported through ice in such a way as to produce a small voltage across the cell. However, the voltages measured were quire small, and the internal resistance of the cell and the resistance of the electrodes were excessively high. The current obtainable was accordingly too small to be of practical use. Also, it is difficult to select and attach electrodes to a protonic conductor, such that the electrodes are non-polarizable, reversible and stable.